A spokesman said: 'Like many organisations, our UK plant was subject to a ransomware attack affecting some of our systems on Friday evening.
Our teams are working to resolve the issue.' It is understood production has still not resumed today, but that the plant was not operating at full capacity when the attack began.
Shadow health secretary Jonathan Ashworth said concerns were repeatedly flagged about the NHS's outdated computer systems, which left it vulnerable to the virus.
The hackers made the attack able to spread itself by using the NSA code, which is known as Eternal Blue.
The Shadow Brokers released Eternal Blue last month as part of a trove of hacking tools that they said belonged to the US spy agency.
She added: 'Windows XP is not a good platform for keeping your data as secure as the modern ones, because you can't download the effective patches and anti-virus software for defending against viruses.'CQC (Care Quality Commission) does do cyber checks on the NHS trusts, on hospitals when they do their visits, and they will be advising NHS trusts to move to modernise their platforms and I think that after this experience, I would expect them all to move forward with modernising.'Ms Rudd said the UK was a world leader in cyber security, adding: 'So far, all we have seen is patients inconvenienced, some hospitals, some doctors making changes to their daily life.'But the fact is no data has yet been accessed and the NHS are brilliantly managing to weave through this disruption.'Labour leader Jeremy Corbyn branded the hackers 'unbelievably disgusting'.
He said: 'What we've now got is a bunch of 21st Century highway robbers that have hacked into our NHS and are basically offering protection money to get the information back in order to treat cancer patients or anybody else.'It's unbelievably disgusting and I've got nothing but contempt for those people that have done it, and I'm sure all of you would share that.'But I'm also very angry that in 2014, there was a one-year renewal of the protection system on the NHS systems which was not renewed after that and not renewed the year after that and so are systems are now not upgraded and not protected.
Cyber security firm Kaspersky Lab said it had obtained digital evidence that fuels suspicions that North Korea was involved in last year's $81 million cyber heist of the Bangladesh central bank's account at the Federal Reserve Bank of New York.